Apparatus for making plate glass



April 13 1926.

A. g. 'EVANS APPARATUS FR MAKING PLAT GLASS Filed June 5, 1.924 v- 5sheet's'sneet 1 www.

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April 13, 1926. 1,580,122`

A. E. EVANS APPARATUS FOR MAKING PLATE GLASS Filed June 5, 1924 '5shee'c-sheet 2 di N. W

,FLE-i315;

. /A/VENYTOR MW@ @Z1 April 13 1926.

Filed June 5, 5 Sheets-Sheet 4' April l13 192e.

5 Sheets-Sheet l y., wml I R 1 v i@ y mm, sqm m L/ wm, .Wm m 4 hm, E M 0v l l E. H ,m www. @v :v m mi y o m l 25wthrefgjf1againSt rapiddeterioration incident Patented Apr. 13, 1926. I*

UNITED/f STATES y 1,580,122 PATENT/formen.

` ALBERT r.. EVANS, or PITTSBURGH,A :PnNNs'YLiTANTA, A'ssIoNor. ToPITTsIiUnenfA PLATE GLASS COMYANY, A. CORPORATION OF PENNSYLVANIA.

:APPARATUS Fon MAKING PLATE GLASS. 1

-Application nleid `Tune 5,

10 making plate glass and particu arly to the means for handling .theglass potsbetween theirfreinoval I'QIII the usual melting andA)'nning'ffurnace, and thepouring of .the glass upon the vcasting tablevandfor regulating' 157 their `temperature.` "Itihas for its principal"ohjectsy-lthe. provision of a tunnel lfurnace "and car handlingconstruction, havingz 11nprovedv means, (l) for securing in aneconomical way, the necessary temperature coni 2Q ditions and forregulating such temperav tures; (2)` vfor securing the movement of theVcars carrying the pots into, through and out p vrofthe furnace; `and (3)for protecting the cars v'carrying 1the pots and the movin means I .tothel'iighlteinperature conditions in the furnace.' Oneembodiment of theinvention is illustrated wherein: -V a A Figure l is a diagrammatlc planv1ew of the apparatusv Fig. A2 is a side elevation thereof. Fig. 3 lisallongitudinal vertlcal `section through thefurnace. Fig. 4 is alongitudinal 'horizontal section on the .liney of 'Fig.*5. Fig. 5 is atransverse- `section on the Lline V`V of Fig. 3. Fig. 6

i is van 'end elevation ofthe furnace. Fig. 7 is a vertical longitudinalsection throughtwo adjoining cars, the one at the left being 40 about toleave the -furnace. Fig. 8.is la section through a car which is about toenter,y and Fig. 9 is aview in elevation' of the 'right end Aof the carabout to leave the furnace; parts of the furnace being -in section.

The furnace or leer is of lthe tunnel type and is designed to be used inconnection with theusual furnace employed forheating and'. lining plateglass in pots preliminary to cast-V ngt into sheets upon the regulationtype of vcasting table. In vthe acce ted practiceiof the. art, the potsare remove from' the melting furnace by means of a craneyafter whichthey are transported to the vicinity of the casting table and seatedupon a base or tun "5 tlc, *At this point the crane is disengaged *intheaccompanying drawings the remov 1924. :anni No. 118,037.

i and the cold glass upon thesurface of the bathfin the pot'isskimmed,.the pot is engagedby: a teeming crane and isicarried to the'castingtable Where it iS teeined or poured across one end of such tableby tilting 00 the pot.` Theperiod of-time required bctween the removalofthe pot from the meltmg furnace Aand thepouring operation necessitatesthe skimming of the pot inVal-l instances -because of the cold skinwhich is 05 f ormed at thesurface', and as 'thisperiod ofv ytimevaries', it is diiiult to have 'the glass always at the properytemperature for pouring when the glassv reaches this stage of theoperation. .Y The present device is designed to avoid thesediiiicultiesby providing a secondary furnace adjacent the castingtablein which the pots are placed as they are brought from theyJn'eltingfurnace, and in which the 1n 4"thelpot-s can be brought to adefinite 75 and uniform temperature preliminary to urlng, thus giving aconsistency at pourmg which 1s the proper one and always the same, andavoiding the necessity of skimming the pot preliminary to casting. Theso avoidance ofslnmmngnvolves a saving of glassand a reductionofflab/or.

Briefly stated, the secondary furnace is in the form of a tunnelkiln orleer through which a track passes for cars upor which the potsaremounted, the4 furnace being of a capacity such as to hold upwards offive or six cars at one time. Thel pots vare removed fromthe' meltingfurnace in thefusual way and placeduupon thecars which are then movedalong the trackand into the furnace.v They are Athen moved step by stepthrough the furnace and duringthis movement, the

glass in the brought to the proper temperature for pouring. VAs a car ismoved linto the entranceend of the furnace, the car at theexit end ofthe'furnace is moved out' ,and ontothe-turn-table, this beingpreferiably accomplished in one movement. The

Vturn-'table takes the'place of the turtle- 100 heretoforev referred toand the pot is lifted `fromthe car on -this turn-table by the teemingcrane and moved tothe casting .table and v poured-'in the usual way..Since the seconde. ary furnace' is located adjacentthe kcasting;- 105,table, the period of time elapsing between p a yof the pot from thefurnace and pouring ofthe glass is relatively short,

at meknnming 'is requiredyand the glass 1s poured at the temperaturewhich is 11 the 'found to be most suitable. The use'4 of the turn-tableis desirable as it acts as a switch e for returning the cars `forre-use, and furthermore, serves to permit the-turning of the pot .to aposition in which it can best be engaged by the tongs of the teemingcrane, this being primarily a consideration Where pots are used of ovalcross section as opposed to potsv having a circular cross section.

Referringrst to the general arrangement as shown in Figs. 1 and 2, 1 isthe tunnel furnace through which the cars 2, 3, 4, 5, etc.

time to engage the car 4 adjacent the outlet end of the furnace and moveit onto the turntable 8; and 12 is the motor operating through suitablereduction gearing for operating the pusher bar 11.

The construction of the tunneljfurnace will be readily understood byreference to vFigs. 3 to 6. At each end of this furnace i is a door 13mounted for vertical movement and designed to be in closed positionexcept when a car 1s being vmoved into the furnace and another one isbeing moved out. These doors are operated by means of chains or cables14 passing over pulleys 15 and operated from air cylinders 16. Thefurnace has an arch -17 as indicated in Fig. 5 and is divided into aplurality of compartments (one for each pot) by the transversevparti-fltions 18 (Fig. 3) so that the different sections may be given differenttemperatures, the method of operation being to gradually increase thetemperature of the glass as the pot progresses through' the furnace.

AGrasis supplied for heating the various compartments by means of theburners 19 .(Fig'. 5) projecting through the wall of the furnace at oneside thereof. The air necessary for giving combustion is suppliedthrough the verticalfiues 20, vand the gases of combustion flow upwardlyand over` the tops of the pots as indicated by the arrows in Fig. 5, alarge part of the heat for the Glass being provided by the reflectionfrom talle arch 17. The gases of combustion, after passing through thefurnace, enter the downwardly directed tiues 21 and after passingthrough the recuperative checker work, escape past the damper 22 to thesta-ck tunnel 23.

The recuperative portion of the furnace extends longitudinally thereofand may be constructed in various ways. As illustrated,

the passageways for the ases from the outlet flues 21 consist of t ehollow tiles 24 having the passages 25, 26 and 27 therethrough (Figs. 3and 5), so that the gases from the flues 21 first pass through thepassages to the passages 26 and thence to the passages 27 leading to thestack. Air to the inlet flue 20 is supplied from the chambers 28 pastthe dampers 29 to the passages 30. From this point, it circulates uppast the tiles 24 through the passages 31 to the passages 32, whichcommunicate with the lower ends ofthe vertical flues 20, the air forcom. bustion purposes being in this manner heated to a relatively hightemperature *preparatory to mixing with the gas from the e burners 19.

The cars which carry the pots preferably each consist of a metalframework 33 (Figs. 7 and 8) carried by wheels 33*JL and provided withtops 34 of refractory material such as clay. These blocks projectvlaterally into proximity with the side walls of the furnace, asindicated at 35 in Fig. 9, which feature in connection with thelaterally projecting blocks 36, serve to partition olf the upper portionof the furnace from the portion below the car tops, thus tending toprotect the metal parts of thecar from the high' temperatures Vwhichnecessarily exist in the upper portipn of the furnace. The blocks 34 onthe succeeding cars also abut and interfit asindicated at 37 (Fig. 7),so that a continuous refractory wall is provided tending to prevent thepassage of heat from the upper portion of the furnace to the lowerportion. Additional protection to the metal work of the cars is also(affordedV bly the use of the series of pipes 38 extending a ong eachside of the furnace beneath the blocks 36, cooling fluid such as water,being circulated through these pipes .from the headers 39 at the endsthereof (Fig. 4).

The cars are moved through the furnace `step by step by means of thepusher bar .11 built up of plates and channel bars as indicated in thecross section shownA in Fig. 9. This pusher' bar andA its supporting andopf erating means are mounted in a passageway 40 extendinglongitudinally of thefurnace and opening upwardly through the bottomthereof. The support of the pusher bar is provided by means of theseries of rollers 4l carried by suitable standards 42 located atintervals along the length of the passageway. On the under side of thebar 1l is a rack bar 42a, and this rank bar is operated by means ofthepinion 43 located in the passageway adjacent-'the entrance end of thefurnace as indicated in Fig. 4 and mounted upon a transverse shaft 44.AThe shaft is operated from the motor 12 through the intermediary of (the'reduction gearing 45 and a worm gear and worm in the casing 46. Thepusher bar is provided with a pair of pivoted dogs and' 218 normallyoccupying the positionsindicated in Figs. 7 and 8 vby reason of theportions@ and 50, which are V heavy enough to counterbalance theportions in advanc'e cf the pivots. Each of the cars is" provided with adownwardly projecting part 51 adapted to be engagedl y 'the'dogs Thedog-s are spaced apart on theif'pusheif bar a distance suchthat when thedog 48emgages-tlie car`2 (see Fig. 2), the dog 47 will engage thefcar tat Vthe outlet end of the furj i V nace, The-spacing is" alsosuch, thatwhen Vthe LpusherI bar is moved ahead`s'o as to carry'the cai` 2 intothe lfurnace so that it occupies the position/ofthe car '3, the 'car' .4,at the outlet end ofthe furnace vvill be f brought to theposition ofthe car 5 on the' turn-table 8. A single movement of the pusherbar,'therefore,vbrings a new car into the furnace, moves the car at theoutletend ofthe furnace out ofthe furnacel and onto Y the turn-table 8,`and moves each of the otherV cars in 'the' furnace Vahead onev carlength.

reduces thetime and labor incident to handling*the',l `carsf to "aminimum, the pot itself being in position. to track 9 to the track 6.v

'In order to protect'the metal Work in the passageway 40 from the heatof the-furnace,

' `a plurality of conduits52 are employedconthe passageway and a coolingHuid-such asA nected .to suitable-headers 53 at the endsY of water is.circulated through these conduits. In order to secure a uniform coolingalong the length lof this passageway and-'along the sides of the furnaceby the conduits 38, a part' of the Huid in each .set of pipes ispreferably suppliedfrom each end thereof, sothat the flow in alternatepipes is in different directions. r 1

-In operation, the pots are supplied to the entrance end ofthe furnaceat periods correspondingl to the casting periods, that is,

every Vseven or eight minutes, so that with a sixv pot furnace, the.pots are inthe furnace about 40 minut-esj During this time, they areraised in temperature about 200 degrees i and themolten'gla'ss in thepots has a temperature -of approximately 2100 degrees when the pots areremoved from the furnace.

As the glass is. cast immediately, no skimf ming is 'requiredand theglass as it reaches the casting table" is at a temperature and degree offluidity most suitable .for this'V stage of the operation. The-use ofthe apf paratus also increases the capacity of the i'nelting"furnace. asthe period of hold-over which is required in the melting furnace isreduced b the period of'time which the pots occupy W ile inthe-secondary furnace.

-lVhatIclaim`is:" 1. In combination in apparatus* for hanlling andtreating pots contaliigmokel device.

glass.preliminaryito.castingthe lassfintof l plates, which comprises', atunnel furnace having a track'therethrough, a seriesfof cars on-thetrack for "carryin'g 'the pot s `,a.1noving Idevice for ,thecarsj'extending longi tu'dinally devicev adapt-edt() engage the carnentto the outletend of the furnace and `alsoi1car-lof but adjacentthereto, and means Ifor reciprornree @di Sai-1jaar ad moved ma) ther forhali-` ofv the' "other cars inlthe.

catedgoutside the entrance end of the furnace,

z5 eating saiddevice so that on 'they forward. movement thereof, saidcar VLnext 'thefoutlet .endof the furnacefismoved otsid ofand dling andAtreating pots containing molten glass preliminary to casting the glassinto plates, which comprises, a,tunnel.;furnace having atracktherethrough, a series 'of cars a turntends from theoiitle't end of the?nace,f`a

pusher device extending flongitudinally f of" forwardv movement suchthat it will move said car adjacent the voutlvetend of the! fur-- nace,out of the furnace and onto theturntable, and at thes'ame time move'said car adjacent .the inlet end of the furnace into the furnace,thereby moving all of the other cars in the furnace ahead one carlength.

3. In combination in apparatus-for handling and treatingpotscontaining-molten glass preliminary to casting the lass into plates,which comprises, a tunne furnace aving a track therethrough,za series ofcars on the track for carrying the pots, a moving device for the carsextending longitudinally o the furnace, engagingmeans on 'such deviceadapted to engage the-car next to the outlet end of the furnace andalso. a car located outside the entrance endof .the fur.- nace,butxadjacent thereto', and`means for reciprocating said device so thaton the'for'-v wardv movement thereof saidl car next the` outlet end ofthe furnace -is moved outside of and away. from 'the furnace and saidcar.

adjacentl the entranceis moved into the furnace, thereby moving. all ofthe other cars in the furnace'V ahead one car length, said engagingmeans compri ing thebackwardmoveinent of said-moving 4, In combination.inapparatus for han'- dling and treating potsA containinfr molten glsspreliminary tocasting the gtlass mt plates, which comprises, a tunnelfurnace having a track therethrough, a series of cars on the track forcarrying the pots, a turntable for the cars to which the track extends.from the outlet end of the furnace, a pusher device extendinglongitudinally of the furnace and provided with a pair of engagingdevices arranged so as to engage respectively, the car in the furnacenext to the outlet end thereof and a car outside the furnace butadjacent the inlet end thereof, and means for giving the pusher device aforward movement such that it will move said car, adjacent the outletend of the furnace, out of the -furnace and onto the turntable, and atthe same time move said car adjacent the inlet end of the furnace intothe furnace, there by moving all of the other cars in the furnace aheadone car length, said engaging devices comprising pivoted dogs adapted toswing to inoperative position during the backward movement of saidmoving device.

5. In combination in apparatus for han- I dling and treating potscontaining molten glass preliminary to casting the glass into plates,which comprises, a tunnel furnace having a track therethrough, a seriesof cars on the trackfor carr ing the pots, a, rack .bar extendinglongitu inally` of the furnace beneath the cars and guided for endwisesliding movement, a plnion engaging the rack bar, means forrotating thepinion back and forth to reciprocate the rack bar, and a pair of pivoteddogs on the bar, arranged so that when the bar is in retracted position,the forward dog will engage` the car in the furnace next the outlet endthereof, while the other dog will engage a car outside the entrance endof the furnace, but adjacent thereto, so that on Vthe forward movementof the rack bar said car at the outlet end of the furnace will be movedout of and away from the end of the furnace, while said Icar outside theentrance end of the furnace will be moved into the furnace therebymoving all of the other cars in the furnace ahead one car length.

6. In combination in apparatus for handling and treating pots containingmolten glass preliminary to casting the glass into plates, whichcomprises, a tunnel furnace iaving a track therethrough and a passagewaylongitudinally of itsibottom opening upwardly, a series of cars on thetrack for carrying the pots, a moving device for the cars extendinglongitudinally of the passageway, means extending upwardly from saiddevice for engaging the cars, conduit means also extendinglongitudinally of the passageway, and means for circulating a coolingfluid through said conduit means.'

In testimony whereof, I have hereunto subscribed my name this 2nd day ofJune, 1924.

"ALBERT E. EVA \S`.

